Method of producing elongated



J. KAFOWI July 6, 1943.

METHOD OF PRODUCING ELONGATED BODIES BY DEFORMATION Original Filed July 24, 1937 lll I V I V 17 M mm A w [W 0 A 3 H, O J 4 5 m :2 E H 7. I 2

6 .4 m 9 1 1 m Mo New u w 2 n BY v v L fi%/, 52 .4 7' TOENEY Reissued July '6, 1943 METHOD OF PRODUCING ELONGATED BODIES BY DEFORMATION Johann Kafowi, Long Island cm; N. Y., assignor of one-half to Friedrich Golds-chmidt, Prague,

clcchoslovakia Original No. 2,200,231.- dated Mar 5. i940, Serial No. 155,559,-Jnly 24, 1937. Application for reissue May 0,1942, Scl'ill No. 441.922

(Cl. ZO'I- -IO) 6 Claims.

This invention relates to a-method for producingarticles of metal or any other suitable material, in particular but not exclusively tubes and rods by extrusion.

According to the present invention a blank or billet is heated to a temperature near to but below its melting point before being subjected to an instantaneous impact action such as a hammer blow in a die of a press.

The expression a temperature near to but below its melting point is intended to mean a temperature at which the blank or billet is in an almost plastic condition, that is a condition under which the blank or billet oflers suillcient resistance to tongs or other implements used for inserting it into or positioning it on the die withoutbeing deformed by said tongs or implements. Such a condition of the blank or billet has been found to be ideal for shaping it in or by the die under an instantaneous impact action for the reason that such condition ensures perfect flow of the material which is not checked by loss of temperature occurring between the successive operations of positioning the billet or blank upon or into the die and exerting an instantaneous impact. The kinetic energy or momentum of the latter is transformed into heat which may compensate to some extent for slight heat losses occurring between the positioning of the billet W or blank in or on the. die and the impact.

In carrying the invention into effect any known kind of press may be employed provided that it is capable of exerting an instantaneous impact action upon the blank or billet to be extruded through or shaped-by a die. Inother words the blank or billet must be subjected to the blow of a hammer or plunger which at the moment of impact moves at a speed and thereby acquires Fig. 2 is asectional view along lines' II--II in Fig. 1. and

Fig. 3 a vertical section with parts in elevation of apart of the press, showing on an enlarged scale a severing plunger within the die,

'position' of plunger i as shown in Fig. 1.

Referring to Fig. 1 a friction press is shown there provided with two friction disks 2, i, rigidly mounted on a shaft which is iournailed in bearings II, 32 of a frame 23. On one projecting end of shaft Ill pulleys 6', 6" are rigidly mounted for driving a belt drive at different speeds in well known manner. To the other projecting end of shaft a lever 34 is journalled which is pivotally mounted at 35 on frame 32 and is connected through link 36 with a crank lever 21 pivotally mounted at 38 on frame 23. The other end of crank lever 31 is journalled to rod I which is slidably and frictionally held in lugs 38,10 on frame 33 and provided with an elongated slit II.

A disk I is mounted on a spindle 42 provided I with a screw thread cooperating with and passing a screw threaded! portion of frame 33. On the lower end of spindle 42, a tup or plunger I is mounted so that spindle 42 can freely rotateportion 20. The plunger portion 20 is slidably mounted on the guides 22 and is thus movable relative to the plunger 1. The centre part of the plunger portion 20 is formed into a punch or patrix 2| which is adapted to move into a mold II. The mold i1 is built into or on the anvil bed 28 of the press or is made integral therewith and is provided with a die It for shaping thearticle. The die II has a bore 2! which corresponds to the outer diameter of the article to be produced' The mold l'l receives the blank 24 which preferably has the shape of a hello cylinder.

The guide bars 22 are provided with heads 22' at their lower ends on which the intermediate plunger portion 20 rests in the initial or rest One end 'of'a lever. 4 is pivotally mounted at I! on frame 22 and at its other end pivotally connected with the insert it which is rigidly mounted on plunger i. A pin 42 on lever l slidably engages the slit ll.

In operation, a'blank 24 the mass of which is small compared with that of plunger I, is heated to a temperature close to but below its-melting temperature. Thus,' for instance, a blank of brass or copper should be heated to above.850

- C. The hot blank is positioned in mold ll, upon for use in removing the burnai'ter the production of a tube. I

gages disk 8.

die II, and immediately thereafter shaft 30 is moved to the right so that disk 2 frlctionally en- Diak 2 revolves in the direction of tion can be forced upon plunger I and thereby kinetic energy ormomentum of the latter in the V moment of the impact can be obtained.

Thus thetup or plunger I and plunger portions 20, 2] are first forcibly dropped from their uppermost rest position shown in Fig. 1 until patrix or mold cover 2| contacts and comes to a rest on blank 24. The downward drive of plunger i is continued at increasing speed while the guide rods 22 slide through the openings 26 in the portion 20 and the-mandrel 23 slides through the patrix 2i into position through and projecting below the die or matrix II.

It will be appreciated that the downward movement of plunger I with insert I! and mandrel 23 goes on practically without resistance until patrix 2| has contacted and been seated .upon the heated blank 24, mandrel 23 has been passed through the registering holes of the patrix and the blank into the aperture 29 of matrix I8 and projects below the latter, and that during this downward movement the speed and momentum of the heavy plunger I increase continuously. However, as soon as the lower sur- The downward movement of plunger I withinsert l9 and mandrel 23,as well as of patrix 2I is so fast that the blank does not cool down considerably. Moreover, by the blow exerted upon it. some heat is developed which to some extent compensates for heat losses. Thus the blank substantially retains its plastic state during shoping. The shaped article, in this exemplification of the invention forming a tube, remains suspended downwardly from the matrix until it is cooled sufficiently to solidify.

It will further be appreciated from the drawing that lever 4 is taken along by insert 19 of plunger 2 during the latter's rapidly increasing downward movement, and that in the lower most position of the plunger and when the shaping of the blank has been substantially completed, pin 43 has moved downwardly in slit 4,! so as to take along rod b and to trip the linkage connected with it. Thereby shaft 30 is shifted to the left to a neutral position from that shown in Fig. l, breaks the frictional engagement between the disks 2 and 3, and ceases to forcibly drive plunger I further downward; disk 3 is stopped immediately thereaftenand discharges its kinetic energy as a reduced pressure upon plunger I, whereupon only the weight or the latter and the parts connected therewith rest on top of I2 but takes the latter along when rotated.

heads 22' of the guide rods 22 engage the plunger movement disk 3 gradually engages portions of ,new sufficiently hot bank in the mold.

which serves this purpose is shown in the drawor, as is shown in the drawing, mechanically.

In order to return the plunger I and the parts connected therewith into its uppermost rest position, shaft II! is moved further to the left, preferably by hand, so that disk 6 frictionally engages disk 3 and, since disk 6 is rotated in the same direction indicated by arrow 44 as disk disk 3 will now be rotated in the opposite direction. Thereby spindle 42 is screwed upwardly. taking along plunger I and the mandrel 22 rigidly connected therewith, while the patrix 2 I remains in its lowermost position owing to its weight, whereby the mandrel is stripped from theextruded article. When the plunger I has been raised to such an extent that the lower portion 20, the latter is lifted and the plunger I with the patrlx 2| eventually return to their uppermost rest position,

It will be appreciated that during this upward disk 6 nearer to shaft 3|! whereby its speed, as well as the speed at which plunger i rises are reduced. When plunger I approaches its uppermost position, lever 4 trips rod 5 slightly upwardly, whereby through the linkage previously described shaft 30 is somewhat shifted to the right and disengages disk 3 from disk 6, while due to the action of inertia, disk I with spindle 42 continue their rotation until plunger I arrives in its rest position and is held thereby the selflocking action of the screw threads on spindle 42 and frame 33. A new cycle of operation is then started preferably manually by moving shaft 30 so far to the right that disk 2 frictionally engages again disk 3, and by positioning a When the extrusion of a tube is completed as described, the extruded article must be freed of the burr which is that. part of the extruded article, shown at 21 in Fig. 3, which remained in the matrix l8 and is still connected with the finished tube, so that the latter can be removed downwardly from the die. A severing device ing and comprises a hollow severing plunger I4 which, in the form shown, is tapered towards its lower sharp edge. The conical outer surface I4 is roughened to cause the severed burr to adhere to the severing plunger I4 when it is lifted. The adherence of thematerial to the severing plunger is increased by the contraction of the material which'is now cooling down rapidly but was still quite hot when plunger I4 was driven into' it.

This severing plunger can be inserted manually For the latter purpose the plunger is pivotally held in one end of fork IE on which guide rolls 4] are journalled. A casing 48 open on both front ends is provided with a slit 4! on top through which a pin IE on one arm of fork I5 projector Another pin IS on that fork is arranged to enter that slit. The right end of fork ii is journalled to an arm 13 on a nut 50 which engages a screwthreaded spindle 12. The right end of spindle I2 is smooth and passes a bearing 51 connected with frame 33; on its projecting end a small flywheel 52 is mounted. The left end of spindle I2 is also smooth and passes through a sleeve l2 on which bevelled gears Ill, II are mounted.- Sleeve 52 and the left end of spindle II are connected by a key and slot coupling, so that sleeve 52 can slide longitudinallyon that end of spindle A small disk I is mounted on a spindle I, jourand severing plunger ll to the left and eventually allowing the latter to rest upon the burr 21 as shown in Fig. 3. Just before plunger It arrives I in this position, pin l5 engages the back of gear II and moves the latter together with sleeve 52 and gear III to the left, thereby disconnecting the gears 9 and Ill. The motion of severing plunger I l is completed by the inertia of fly-wheel 52. The dimensions of all the cooperating parts are such that plunger I just arrives in its uppermost rest position when plunger it arrives in its rest position on burr 21. At this moment shaft." is shifted somewhat to the right by the action of the linkage between rod 5 and that shaft as previously described.

Now shaft is preferably manually moved tually insert ill of plunger l strikes from above the patrix 2!; this is shown in Fig. '3. This blow upon the patrix is translated to severing plunger I4 and drives the latter through the burr whereby the latter is cut off from the tube. This severing motion of plunger II is permitted by the position of the guide rolls 4! in casing 48 as shown in Fig. 3, where fork I5 is moved to its uttermost position at the left. The height of severing plunger [5 is preferably so little that rod 5 is dropped by lever I when the cutting edge of plunger ll contacts matrix l8, whereby disk 2 is disengaged from disk 3 in the manner previously described. I

Upon shifting shaft 30 fully to the left, disk 8 engages disk 3 and thereby lifts plunger I and eventually patrix 2| in the manner described above. Simultaneously disk 6 also engages disk 1 and rotate; gear 9 with which gear II has been brought into engagement (by manually turning wheel 52) whereby spindle l2'is rotated in opposite direction and moves nut 50 and thereby fork ii to the right, which takes along the severing plunger It with the burr adhering to its outerrough surface It. When fork l5 reaches its uttermost position to the right, pin I6 engages gear l0, shifts it and sleeve 52 as well as gear ll to-the right, whereby the'latter is'disengaged from gear 9.'- When plunger l arrives in its uppermost position, lever 4 trips rod 5 and shifts shaft 30 somewhat to the right, whereby disk 6 is disengaged from disk 3 and the'press is ready for a new cycle of operation. In order to bring about at the proper instance the severing operating just described, fiy-wheel 52 is to be turned by hand so far that gear l3 engages gear 8 just before disk 6 is again brought into engage-' ment with disks 3 and 'l for performing the severing operation.

While the next blank is inserted and shaped in the die, plunger It is idle in its position shown in Fig. 1 and the burr may be removed from it by hand, or plunger 14 with the burr adhering to it may be replaced by a clean severing plunger.

The apparatus described is particularly suitable for carrying out the method of the present invention as the sliding central portion 20, I9 ensures the full force or momentum of the stroke of the plunger being applied to the blank.

I claim as my invention:

' 1. A method of producing articles whichare I relatively long compared with their cross-section, such as tubes and rods, comprising heating a blank or billet to a temperature near to but below its melting point, and subjecting the blank to an instantaneous impact blow to extrude the material through a die to form the elongated article.

2. A method of producing articles which are relatively long compared with their cross-section, such as tubes and rods, comprising heating a blank or billet to a temperature near to but below its melting point, subjecting the blank to an instantaneous impact blow to extrude the material through a die to form the elongated article and severing by a subsequent impact blow of sufficient. momentum exerted upon a temporarily interposed cutting implement, the burr, formed from the residue of the blank, from the extruded article.

3. In a method of shaping metallic articles in the heat and under pressure,.-the steps of positioning a metallic blank or billet heated to a temperature near to but below its melting point freely, i. e., essentially spaced from any side wall, upon a die the shaping elements of which confine an opening adjacent to and covered by said blank or billet, the horizontal area of said opening being considerably smaller than the area of the largest horizontal cross section of said blank or billet, and subjecting said blank or billet to an instantaneous impact blow directed toward said opening, the momentum of said blow being sufiicient to extrude instantaneously the blank or billet through said opening.

4. In a method of shaping metallic articles in the heat and under pressure, the steps. of positioning a metallic blank or billet heated to a temperature near to but below its melting point free- 1y, i. e.,-essentially spaced from any side wall,

upon a die the shaping elements of which confine an opening adjacent to and covered by said blank or billet, the horizontal area of said opening being considerably smaller than the area of the largest horizontal cross section of said blank or billet, and subjecting said blank or billet immediately thereafter to an instantaneous impact blow directed toward said opening, the momentum of said blow being sufllcient to extrude instantaneously the hot and almost plastic blank or billet through said opening.

5. In the method of shaping in the heat and under pressure metallic articles, the steps of positioning a metallic blank or billet heated to a temperature near to but below its melting point freely, i. e., essentially spaced from any side wall,

upon'a die the shaping elements of which contaneous impact blow of a momentum sufficient to.

extrude instantaneously said hot blank or b-illet through said opening, and discontinuing said forcible drive of said plun w n s id blow is being exerted.

6. In a method of shaping in the heat and under pressure metallic articles, the steps or mum; a metallic blank or billet heated to a temperature near to but below lts melting point freely, i. e.,

essentially spaced from any side wall, upon a die the shaping elements of which confine an opening adjacent to and covered by said blank or billet,

the horizontal area of said opening being considerably smaller than the area of the largest horizontal cross section of said blank or billet,

and,thereby momentum toward said blank or billet and said die and opening therein, so as to exert upon said blank or billet an instantaneous impact blow ,0! a momentum sufllcient to extrude instantaneously said hot blank or billet through said opening, and reducing considerably the force of said drive of the plunger when said blow is being exerted. V

A JOHANN KAFOWI.

. forcibly driving a'plimger with increasing speed 10 

